A trans-Neptunian object (TNO), also written transneptunian object, is any minor planet in the Solar System that orbits the Sun at a greater average distance than Neptune, which has an orbital semi-major axis of 30.1 astronomical units (au).
28978 Ixion (, provisional designation 2001 KX76) is a large trans-Neptunian object and a possible dwarf planet. It is located in the Kuiper belt, a region of icy objects orbiting beyond Neptune in the outer Solar System. Ixion is classified as a plutino, a dynamical class of objects in a 2:3 orbital resonance with Neptune. It was discovered in May 2001 by astronomers of the Deep Ecliptic Survey at the Cerro Tololo Inter-American Observatory, and was announced in July 2001. The object is named after the Greek mythological figure Ixion, who was a king of the Lapiths.
20000 Varuna (provisional designation 2000 WR106) is a large trans-Neptunian object in the Kuiper belt. It was discovered in November 2000 by American astronomer Robert McMillan during a Spacewatch survey at the Kitt Peak National Observatory. It is named after the Hindu deity Varuna, one of the oldest deities mentioned in the Vedic texts.
Orcus is a large trans-Neptunian object with a large moon, Vanth. It has a diameter of 870 to 960 km, the size of or somewhat smaller than the Inner Solar System dwarf planet Ceres. Orcus is generally accepted by astronomers as a dwarf planet, although there is some doubt. The surface of Orcus is relatively bright with albedo reaching 23 percent, neutral in color and rich in water ice. The ice is predominantly in crystalline form, which may be related to past cryovolcanic activity. Other compounds like methane or ammonia may also be present on its surface. Orcus was discovered by American astronomers Michael Brown, Chad Trujillo, and David Rabinowitz on 17 February 2004.
(26375) 1999 DE9 (provisional designation 1999 DE9) is a trans-Neptunian object. Light-curve-amplitude analysis shows only small deviations, suggesting (26375) 1999 DE9 is a spheroid with small albedo spots. Measurements by the Spitzer Space Telescope estimate that it is 461 ± 45 km in diameter. It was discovered in 1999 by Chad Trujillo and Jane X. Luu. It is possibly a dwarf planet.
38628 Huya ( hoo-YAH; provisional designation 2000 EB173) is a binary trans-Neptunian object located in the Kuiper belt, a region of icy objects orbiting beyond Neptune in the outer Solar System. Huya is classified as a plutino, a dynamical class of trans-Neptunian objects with orbits in a 3:2 orbital resonance with Neptune. It was discovered by the Quasar Equatorial Survey Team and was identified by Venezuelan astronomer Ignacio Ferrín in March 2000. It is named after Juyá, the mythological rain god of the Wayuu people native to South America.
(90568) 2004 GV9 (provisional designation 2004 GV9) is a trans-Neptunian object that was discovered on April 13, 2004 by NEAT. It has been listed as a cubewano by the Minor Planet Center. It was discovered on 13 April 2004 by NEAT. It has been observed forty-seven times, with precovery images back to 1954. The object has an orbital period of 273.88 years. Its maximum possible distance from the Sun (aphelion) is 45.62 AU, and its closest (perihelion) is 38.7 AU, and currently 39.7 AU from the sun. It has an inclination of 21.9718, and eccentricity of 0.082.
(55565) 2002 AW197 (provisional designation 2002 AW197) is a classical, non-resonant trans-Neptunian object from the Kuiper belt in the outermost region of the Solar System, also known as a cubewano. With a likely diameter of at least 700 kilometers (430 miles), it is approximately tied with 2002 MS4 and 2013 FY27 (to within measurement uncertainties) as the largest unnamed object in the Solar System. It was discovered at Palomar Observatory in 2002.
(55637) 2002 UX25 (provisional designation 2002 UX25) is a trans-Neptunian object that orbits the Sun in the Kuiper belt beyond Neptune. It briefly garnered scientific attention when it was found to have an unexpectedly low density of about 0.82 g/cm3.
(55636) 2002 TX300 is a bright Kuiper belt object in the outer Solar System estimated to be about 286 kilometres (178 mi) in diameter. It is a large member of the Haumea family that was discovered on 15 October 2002 by the Near-Earth Asteroid Tracking (NEAT) program.
(208996) 2003 AZ84 (provisional designation 2003 AZ84) is a trans-Neptunian object with a possible moon located in the outer regions of the Solar System. It is approximately 940 kilometers across its longest axis, as it has an elongated shape. It belongs to the plutinos – a group of minor planets named after its largest member Pluto – as it orbits in a 2:3 resonance with Neptune in the Kuiper belt. It is the third-largest known plutino, after Pluto and Orcus. It was discovered on 13 January 2003, by American astronomers Chad Trujillo and Michael Brown during the NEAT survey using the Samuel Oschin telescope at Palomar Observatory.
(145452) 2005 RN43 (provisional designation 2005 RN43) is a classical Kuiper belt object. It has an estimated diameter of 679+55
−73 km. It was discovered by Andrew Becker, Andrew Puckett and Jeremy Kubica on 10 September 2005 at Apache Point Observatory in Sunspot, New Mexico. Brown estimates that it is possibly a dwarf planet.
(84922) 2003 VS2 is a trans-Neptunian object discovered by the Near Earth Asteroid Tracking program on 14 November 2003. Like Pluto, it is in a 2:3 orbital resonance with Neptune and is thus a plutino. Analysis of light-curve suggests that it is not a dwarf planet.
(469372) 2001 QF298, provisionally known as 2001 QF298, is a resonant trans-Neptunian object that resides in the Kuiper belt in the outermost region of the Solar System. It was discovered on August 19, 2001 by Marc W. Buie. 2001 QF298 is a plutino, meaning that it is locked in a 3:2 orbital resonance with Neptune, much like Pluto.
(145451) 2005 RM43 (provisional designation 2005 RM43) is a trans-Neptunian object that resides in the scattered disc region beyond the Kuiper belt. It was discovered on 9 September 2005, by American astronomers Andrew Becker, Andrew Puckett and Jeremy Kubica at Apache Point Observatory in Sunspot, New Mexico. It measures between approximately 500 and 650 kilometers in diameter.
(40314) 1999 KR16 is a trans-Neptunian object on an eccentric orbit in the outermost region of the Solar System, approximately 254 kilometers (158 miles) in diameter. It was discovered on 16 May 1999, by French astronomer Audrey Delsanti and Oliver Hainaut at ESO's La Silla Observatory in northern Chile. The very reddish object is a dwarf planet candidate and has a rotation period of 11.7 hours.
65489 Ceto, as a binary also (65489) Ceto/Phorcys, is a binary trans-Neptunian object (TNO) discovered on March 22, 2003, by Chad A. Trujillo and Michael Brown at Palomar. It is named after the sea goddess Ceto from Greek mythology. It came to perihelion in 1989.
(524366) 2001 XR254, provisional designation 2001 XR254, is a trans-Neptunian object and binary system from the classical Kuiper belt, located in the outermost region of the Solar System. The cubewano belongs to the cold population and measures approximately 171 kilometers (110 miles). It was first observed on 10 December 2001, by astronomers at the Mauna Kea Observatory, Hawaii. Its 140-kilometer sized companion was discovered by the Hubble Space Telescope in June 2006.
2018 VG18 is a distant trans-Neptunian object that was discovered well beyond 100 AU (15 billion km) from the Sun. It was first observed on 10 November 2018 by astronomers Scott Sheppard, David Tholen, and Chad Trujillo during a search for distant trans-Neptunian objects whose orbits might be gravitationally influenced by the hypothetical Planet Nine. They announced their discovery on 17 December 2018 and nicknamed the object "Farout" to emphasize its distance from the Sun.
